im not sure a loose backing plate would cause your lack of braking though. I wonder if it was the ABS kicking in as a2dadamm mentioned.... makes a bit of noise that could be described as grinding

 

I was cleaning everything up on my truck yesterday,took the caliper off and cleaned some rust and dust.Regreased the wheel bearing.I got a mile down the road I hear this loud thumping noise,I thinking wth?Come to find out I forgot to tighten all the lug nuts on the rim.(YIKES)

 

I would have to say it really sounds like the ABS unit...

 

Chi MiGwetch Everyone!! I got it into a shop day before Thanksgiving and they did a complete inspection. They quoted abt $7,000.00 in repairs. Half the stuff on "their" list doesn't need to be done. Like oil change, filter, fluids, etc (done in Oct) said i need a new thermostat an gasket (just replaced that beginning of Oct) radiator backflush new fluids etc (did that same time i flushed the radiator an replaced the thermostat in Oct) ABS Modulator ($1,280.48 Umm Hello 3 cent fix with black electrical tape lol) i just unplugged the ABS thing an bam i can operate my brakes on my own which is better on my sanity. The major things are my Left & Right Upper & Lower Ball Joints, L & R Wheel Bearings and Idler Arm according to the 4X4 place that is helping offset the $7 G's the Big Box Place wanted. I was made to drive it down to other shop this a.m. The rear brake caliper was missing a bolt apparently. (the asshat I had to the drivers side rotors at end of summer this yr is so lucky he's not in Michigan I am not mechanically smart but I'm more than willing to learn the stuff needed to fix my own truck an keep her running good) & the other bolt to it was barely threaded into caliper. Upon driving it down to shop it became so stuck onto rotor that the brakes were all locking up & the god awful grinding & shuddering was a complete white-knuckled nightmare!! So All in All I still need to get wheel bearings and ball joints an idler arm replaced. So keeping fingers crossed. I thanks you all for your input & suggestions. Have a Great Weekend Everyone :-)

 

you could replace the blazer for less than that!!

 

You a mechanic thats trying to take advantage of you forsure just because your a lady.They think the can pull a scam on you by trying to charge rediculous prices for things that dont need to be done.Changing ball Joints isnt difficult Im sure with advice from us on this site you could it.Theres noway you vehicle could need that much in repairs.You can buy a decent Jimmy for under $3ooo.Wish I was closer to you Id be willing to lend a hand to help ya out.
So btw how far up in Northern Mi are you?Im in the bottom of the thumb area

 

welcome from michigan...sorry to see it looks like someone is trying to take you for a ride.
those figures are way over blown

 

I ticks me off when I see mechanics trying to pull scam on ladies cause they think they are nieve and dont know many better.Maybe You werent reading inbetween the lines and he gave you that figure to scare you off cause he didnt want to do the work.I cant see someone quoting those customers to somebody then the customer goes uuuuuh ok do it.

 

do the wheels lock up, is there severe pedal travel, does the pedal come on strong and fade to soft?

check to make sure you didnt get any break fluid on your discs or rotors (likely to cause slip and because its oil doesnt like to burn off), make sure nothing metallic has come between the rotor and the pad (disintegrating dust backing, squealer tips, brake clips), bleed the brakes per manual for an abs 4wd vehicle as there is a specific pattern you must use for abs vehicles. if i recall right its RR, RL, FR, FL.

now if you have so spend money check brakes lines first, check your brake resivour for cracks or leaks, then check your master cylinder as its not uncommon for the diaphragm in them to blow out and "sometimes" it give good pressure and good stopping power and sometimes it doesnt.

could be a number of things but if the brakes didnt lock up "like on black ice" the abs would kick in and it makes a loud grunt that sounds like grinding. which the sound comes from around the pedals usually as this is where the mechanisms generally are and can be mistaken to come from the passenger side i suppose